Purpose: To measure the drift of ocular alignment following strabismus surgery utilizing adjustable sutures.
Methods: 106 patients, age 12 to 84 years, underwent adjustable suture strabismus surgery with follow-up of 0.5 to 4 years (mean 24.3 months).
Results: For all subjects measured on distant fixation, there was a mean undercorrection drift of 8.3 + 2.3 PD from week 1 to 48 months postoperatively (p = 0.005). Patients with exotropia demonstrated an undercorrection drift on distant fixation from week one to two years (mean 10.1 + 3.5 PD, p = 0.023). Patients who underwent recession surgery developed a mean 9.1 + 3.3 PD undercorrection drift from week one to three years (p=0.031). Patients who had unilateral recession and resection surgery showed a mean 6.8 + 2.9 PD undercorrection drift from week one to 18 months (p = 0.049). Patients with constant or intermittent postoperative stereopsis had a statistically significant undercorrection drift (< 5.1 P.D.) at certain postoperative periods (p< 0.042), while those without stereopsis had no significant drift.
Conclusion: Most patients developed a general drift toward undercorrection, especially following recession or recession with resection surgery and those with exotropia. Surgeons should consider creating a mild overcorrection at time of suture adjustment, while avoiding long term diplopia.